SainSmart 3018-PROver CNC Router – Assembly Errata and Initial Review

January 18, 2020

The materials provided are good: heavy and well-machined aluminum, acceptable quality electronic and mechanical components and fasteners. The 3018-PROver is not nearly as “assembled” as the purchasing data indicates. You can download the assembly video or the manual and see for yourself – there are a couple of hours of assembly work, and there will be much consulting of the online manual, the video, and this errata while you are at it. The three major subsystems are mechanically assembled, but have not had the electrical components, wiring and many little parts mounted, and two major subsystems need to be bolted together. And since the instructions leave a lot for you to figure out, if you’re easily frustrated: choose another project.

The PROver version is based on Open Source software and incorporates its own motion controller software: GRBL 1.1. It does not need to be connected to your computer while the router is cutting. Most people will use Open Source CAD software, which does not come with the unit.

There is also a “3018 Pro MX3” version which requires that you purchase the Mach 3 software for $175, has a different main controller board and a different hand controller, and requires a Windows computer to run Mach 3 while the router is cutting. The 3018 PROver is a better choice for most people, as it avoids this expense and complexity. Mach 3 is motion-control software, not the CAD software. You will still need to find that.

The 3018-PROver controller is based on Arduino. The main controller runs the GRBL 1.1 software developed for Arduino and comes with its own hand controller. Hand controllers for other models, like the one for the MX3 version, are not compatible.

Source code for GPL-licensed software in this unit is not on the SainSmart web site as far as I can tell, and it looks like SainSmart still needs to learn how to comply with the licenses to the GPL binary software they distribute, and directly distribute the source code on their own site. I do not know what differences exist from the GRBL 1.1 developer’s source, but I suspect some might exist for the hand controller.

This machine will be covered with chips after operation and will require some wiping down, including passing some sort of wipe inside of the T-slots. I will try to improvise a chip vacuum for mine, no such thing is available to buy.

To find the assembly video, search for Sainsmart Genmitsu CNC Router 3018-PROVer Build. A few hits down from the top of the search on Google, there is a wiki page for the device at . You can also find this directly on the wiki, but the indexing is based on SKU numbers. There are assembly videos for other models on Youtube, which you might find helpful.

Most of the tools required for assembly are provided. In addition, you will need a wire cutter to remove two wire ties used as a shipping lock, and a container of light oil to lubricate the lead screws, and some electrical tape to wrap moving wires together.

You will need to download the manual and display it on a big screen. That is the only way you will be able to see the photos adequately to be able to assemble the unit. The photos are in a printed manual provided with the unit, but too small and too low-resolution to tell what you should be doing.

Here are the errata I noted during assembly:

Step 1: You will need to provide your own wire cutter.

Step 2: You are told to mount 6 wire holders, but the photo only shows where two of them go! The video is similarly unhelpful! The second two go on the opposite side, identically to the first two. The third two go on the outside of the frame, on the same side as the stepper motor, opposite the two installed inside.

Step 3: The four wire holders mount on opposite sides of the metal piece. The photos don’t quite show this completely.

Step 5 and 6: The long end of the distance tool is held against the back of the frame, inside the channel. The last slider nut should be against the end of the distance tool. Because of the distance tool, everything lines up well and the 12 bolts go in a lot more easily than I expected.

Step 8: The square projection on the slide nut goes outward.

Step 9: Peel the protective film off of both sides of the acrylic sheets. They are clear, tinted blue, once you do that. Hold the sheet so that it fits the shape of the leg of the Y-Z assembly. That is the correct orientation. Put the bolts through from the outside, and put the slide nuts on the other side by hand, one turn only. Orient the slide nuts horizontally, and then push the acrylic sheet to the channel so that the slide nuts insert into the channel. Turn the bolts, and the slide nuts will seat correctly.

Step 10: There is an error on this page. Where they specify the Y+ and Y- connecting wires, they actually mean X! The VER- numbers are correct, Y should be X.

The main controller is attached to two beams, each of which has four channels. The X- limit switch wire must be run behind the main controller along the top of the bottom beam, looping to the front on the side where the controller has the USB connector. The cover strip goes over the wire on the top channel of the bottom beam.

Step 11: It may be necessary to temporarily remove the wire holders next to the limit switches so that there is enough space to insert the plugs into the limit switch sockets. Put the wire holders back afterward.

Step 13: There are different plugs on each end of the stepper motor wires.

Step 15: By “black cover”, they mean the black plastic nut on the barrel of the emergency stop button. Remove that and the square lock washer. Put the switch into the plate, and then put the lock washer on the switch from the back, with the pointy corners facing the metal plate.

This button is unusual: push to stop, twist to release.

Step 16: Whew! A lot left out here! You are supposed to pass all of the Z wires through a piece of the nylon braided web to protect them from friction. But the piece I was provided, although it can be expanded somewhat, doesn’t expand sufficiently to do this. I wrapped the wires with electrical tape.


Before you connect the router to your computer, you can play with it using the manual controller. This is non-intuitive though. I noticed that the files included on the SD card would run into hard limits (trip the limit switches) if run with the router starting in the home position. You will have to move X, Y, and Z close to the center of their operation before starting.

The limit switches are confusing. If you are stuck on a limit, which is sure to happen, run the reset function. Move the stuck axis until it stops again – the limit switch will halt the system when it is set, and again when it is cleared! Run the reset function a second time. Then you can move the axis as expected. At this writing I am not sure if configuration will make this easier.